/* http://james.padolsey.com/javascript/special-scroll-events-for-jquery/ */
(function () {
  var special = jQuery.event.special,
    uid1 = "D" + (+new Date()),
    uid2 = "D" + (+new Date() + 1);
  special.scrollstart = {
    setup: function () {
      var timer,
        handler = function (evt) {
          var _self = this,
            _args = arguments;
          if (timer) {
            clearTimeout(timer);
          } else {
            evt.type = "scrollstart";
            jQuery.event.dispatch.apply(_self, _args);
          }
          timer = setTimeout(function () {
            timer = null;
          }, special.scrollstop.latency);
        };
      jQuery(this).bind("scroll", handler).data(uid1, handler);
    },
    teardown: function () {
      jQuery(this).unbind("scroll", jQuery(this).data(uid1));
    }
  };
  special.scrollstop = {
    latency: 300,
    setup: function () {
      var timer,
        handler = function (evt) {
          var _self = this,
            _args = arguments;
          if (timer) {
            clearTimeout(timer);
          }
          timer = setTimeout(function () {
            timer = null;
            evt.type = "scrollstop";
            jQuery.event.dispatch.apply(_self, _args);
          }, special.scrollstop.latency);
        };
      jQuery(this).bind("scroll", handler).data(uid2, handler);
    },
    teardown: function () {
      jQuery(this).unbind("scroll", jQuery(this).data(uid2));
    }
  };
})();
